Valmet Corporation

Valmet Paper Machinery Inc.

Metso Paper Inc.

Valmet Technologies, Inc.

Petri Paloviita

Jukka Koskinen

Rauno Verner Rantanen

Markku Lummila

Hannu Korhonen

Petri Päivä

Jukka Linnonmaa

Jussi Kangas

A method and apparatus for applying a coat mix to a high-speed running board or paper web by accurately premetering and pre-smoothing the applied coat with an applicator apparatus and then minimally doctoring the applied coat with an air knife. The applicator apparatus has a narrow slot-orifice extending in a cross-machine direction for facilitating high-speed laminar flow of coating mix into a gap region defined by confronting surfaces of the applicator apparatus and the web. The applicator apparatus has a member for directing the ejected coating mix in the gap region in a direction reverse to a travel direction of the web so that only a predetermined portion of the ejected coating mix is allowed to form an applied coat on the web. This accurate premetering of the coating mix by the applicator apparatus permits an operator to readily optimize the subsequent process of doctoring the applied coating with an air knife.

Blade metering unit and method for blade-coating a material web

A method and apparatus for applying a coat mix to a high-speed running board or paper web by accurately premetering and pre-smoothing the applied coal with an applicator apparatus and then minimally doctoring the applied coat with an air knife. The applicator apparatus has a narrow slot-orifice extending in a cross-machine direction for facilitating high-speed laminar flow of coating mix into a gap region defined by confronting surfaces of the applicator apparatus and the web. The applicator apparatus has a member for directing the ejected coating mix in tho gap region in a direction reverse to a travel direction of the web so that only a predetermined portion of the ejected coating mix is allowed to form an applied coat on the web. This accurate premetering of the coating mix by the applicator apparatus permits an operator to readily optimize the subsequent process of doctoring the applied coating with an air knife.

A method and apparatus for controlling the coat profile in short dwell time coaters and similar apparatuses in which the coating mix is applied to the web, over a brief time interval, in an application chamber disposed immediately upstream of a doctoring element. Excess coating mix flows counter to the running direction of the web over the front edge of the application chamber. The distance between the web and the front edge of the coating chamber is adjustable, allowing the cross-machine profile of the coating to be controlled.

Method and apparatus for controlling the coat profile in coaters based

Investigations have shown that curtailing the entry of air between the coater backing roll (3) and the web (5) being coated can offer a significant reduction in the number of uncoated blotches. By virtue of preventing the occurrence of such coat defects, the rotational speed of the kiss roll (2) in kiss roll coaters can be reduced. The invention is based on pressing the web (5) being coated against the backing roll (3) from the opposite side of the web (5) relative to the backing roll (3) at a point preceding the nip between the kiss roll (2) and the backing roll (3), whereby air is prevented from entering between the web (5) and the backing roll (3). The means employed for pressing the web (5) against the backing roll (3) is an air jet to avoid imposing additional stress on the web.

Method and assembly for preventing air entry between a moving material

A method and device for keeping a coating rod and a rod cradle in a bar coater clean and for preventing leakage of the lubrication and/or cooling water used in the bar coater is disclosed. The invention is intended for a bar coater in which the coating rod is, supported revolvingly in a rod cradle substantially over its entire length. The rod cradle is attached to the frame constructions of the coater. The rod cradle is also provided with at least one groove substantially parallel to the coating rod and open towards said coating rod, in which grooves(s) water is circulated to lubricate, cleanse and/or cool the coating rod and the rod cradle. The coating rod is loaded towards the base to be coated by loading the rod cradle. The rod cradle and the sealing lips of the rod cradle are loaded so that the loading seals the glide faces between the coating rod and the rod cradle substantially over the entire length of the rod cradle and prevents leakage, or at least substantially reduces leakage, from the water grooves.

Growing community of inventors

Vantaa, Finland

Petri Paloviita